This invention relates generally to furnaces for the burning of used oil and, more particularly, to a retention head on the end of the burner nozzle assembly for use in controlling the flow of combustion air into the burner chamber of a multi oil furnaces to provide better control of the flame into the burner chamber.
Multi oil furnaces are similar to standard oil burning furnaces, but have been adapted to handle oil products that have been previously used in a traditional lubricating operation, such as used crankcase oil up to 50 SAE, used transmission fluid, and even #2, #4 and #5 fuel oils. Such oil products can have significantly varying viscosities and significantly varying burning characteristics, as well. Typically, used oil products are collected into a tank to be supplied to the furnace from a single source. As furnaces are normally operated when the ambient air temperatures are sufficiently cold to warrant the use of the furnace, the supply of used oil to the furnace is normally as cold as the ambient temperature, which requires a preheating of the used oil to more efficiently effect a burning of the used oil products.
The burner nozzle combines a flow of compressed air with the flow of preheated used oil to atomize the used oil and inject a stream of compressed air and atomized used oil droplets into the burner chamber of the multi oil furnace where it is ignited to create a heat source. Known multi oil furnace burner nozzles utilize an in-line burner nozzle configuration coupled directly into the preheater block and are positioned within the air flow stream of combustion air created by an external fan. Furthermore, the required imposition of an igniter mechanism further impedes the air flow of the combustion air into the burner chamber. All of this structure creates turbulences within the air flow stream of combustion air to detract from the efficient operation of the furnace.
Accordingly, it would be desirable to devise a more aerodynamic burner nozzle assembly that would minimize combustion air turbulences and, thereby, increase the burning efficiency of the multi oil furnace.